Centerless grinder



May 8, 1951 Filed July 19, l949 CENTERLESS GRINDER W. OGlLVlE 3Sheets$heet l mv ENTOR Maw 0M 33 W [Wm ATTORNEYS y 3, 1951 w. OGILVIE2,552,447

CENTERLESS GRINDER Filed July 19, 1949 5 SheetsSheet 2 AFTORNEYS W.OGILVIE May 8, 1951 CENTERLESS GRINDER v 3 Sheets-Sheet 5 Filed July 191949 ATTORNEYS Patented May 8, 1951 CENTERLESS GRINDER William Ogilvie,Copt Heath, Knowle, England, assignor to B. S. A. Tools Limited,Birmingham, England, a British company Application July 19, 1949, SerialNo. 105,585 In Great Britain July 24, 1948 Claims.

This invention relates to centreless grinders of the in-feed type, thatis to say, the type in which the grinding wheel (or in some cases theregulating wheel) is moved into and out of engagement with theworkpiece.

It has previously been proposed to employ cam mechanism in order to movethe grinding wheel or the control wheel into and out of operativeposition in timed relationship with automatic feeding of the workpiecesto the throat between the two wheels. Such arrangements are not suitedto hand-feeding of the articles in the machine.

The primary object of this invention is to provide in a centrelessgrinder, employing an infeed cam to control the distance apart of thegrinding wheel and control wheel, novel means to transmit drive to thein-feed cam, automatic means to interrupt the drive to the in-feed camwhen a work-piece has been ground, and manually operable means tore-engage the drive to the in-feed cam to enable another work-piece tobe ground.

The invention will now be more particularly described with reference tothe accompanying drawings in which:

Figure 1 is a diagrammatic plan view of a centreless grinding machineshowing only the parts thereof necessary to illustrate the invention;

Figure 2 is a section taken on the lines A--A of Figure 1;

Figure 3 is a view of a detail.

A regulating wheel I is rotatably supported and driven in any convenientmanner, not shown and a grinding wheel 2 is supported by a bracket 3 andis rotated by any convenient means, not shown. A workpiece support 4 isdisposed in the throat between the regulating and grinding wheels and aworkpiece 5 is shown resting on the support between the two wheels. Thebracket 3 is provided with a nut 6 which engages a lead screw 1supported at its one end in a bush 8 rigid with the frame of themachine. Secured to this end of the lead screw is a hand wheel 9 andalso secured to the lead screw is an abutment sleeve If] between whichand the bush is located a compression spring ll tending to urge the leadscrew axially in a direction to increase the distance between thegrinding wheel and the regulating wheel. The bracket 3 or parts securedthereto form a slide which is supported in any suitable slideway, notshown. The end of the lead screw remote from the hand wheel abuts asplined push rod 12 slidably supported in a splined bore l3 formed inthe machine frame, and the splined push rod is provided with a roller I4which bears on a button I5 carried by a lever l5 mounted on a pivot pinI1 rigid with the machine frame. The end of the lever remote from itspivot axis is bifurcated to provide two arms between which is disposed aroller l8 mounted on a pin l9 secured at its ends in the arms. Acompression spring 20 operates between the machine frame and the leverI6 to urge the roller l8 into contact with an in-feed cam 2| and thisaction is supplemented by the force exerted by the spring II. Thein-feed cam 2| is secured on the upper end of a sleeve 22, hereinaftercalled the cam sleeve, rotatably mounted in an arm 23 in the machineframe, and rotatably mounted within the sleeve is the upper end of avertically disposed spindle 24 whose lower end is supported by an arm 25of the machine frame and having keyed to its lower end a toothed pinion26 meshing with a toothed wheel, not shown, continuously rotated by amotor when the machine is started. Secured by a pin 26 to the spindle isa ring 2'! formed on its upper face with clutch or dog teeth 28 whichare backed off or chamfered and are adapted to be engaged by similarclutch or dog teeth 29 formed on the lower face of a clutch sleeve 30freely mounted so as to be slidable and rotatable on the spindle 24. Theupper end of the clutch sleeve 30 is provided 'with two diametricallyopposite dogs 3|, only one of which is shown, and each slidably engagesa gap 32 formed in the lower end of the cam sleeve 22 so as to provide asliding coupling between the cam sleeve and clutch sleeve which willtransmit rotary motion and enable relative sliding movement of theclutch sleeve relative to the cam sleeve. A coiled compression spring 33surrounds the spindle and abuts at its upper end against a shoulder 34rigid with the cam sleeve and at its lower end abuts against the clutchsleeve which is provided with a face cam 35 urged into contact by thespring 33 with a projection 36 when the mechanism is in the position asshown in Figure 2. The projection 36 is secured to a plunger 31supported in a block 38 rigid with the machine frame and a compressionspring 39 urges the projection towards the axis of the spindle 24. Theplunger is provided with a peg 40 which engages a slot 4| in the blockto limit movement of the plunger. The peg 40 is engaged by an arm 42rigidly secured on a suitably supported rotatable rod 43 from whichdepends an arm 44 hingedly connected to one end of a link 45 whose otherend is connected to an arm 46 depending from a shaft 41 rotatablymounted tions as shown in the drawings. workpiece has been inserted byhand between the grinding and'regulating wheels and, referring ing theposition of rest as shown in Figure 1 a cam 65 movable with the in-feedcam, has operated ejector mechanism, not shown, to remove the ground orfinished workpiece from between the grinding and regulating wheels. Anunground workpiece can now be fed by hand between the wheels and thegrinding operation The clutch sleeve 39 is also formed with a' groove 59which is of V-shaped cross-section and in the position shown in Figure2. is engaged by a V-shaped nose 59 formed on a plunger rod 6| slidablymounted in the block 38 and urged towards the spindle 24 by acompressionspring 62. The plunger BI is provided with a peg 53 which engages a slot64 formed in the block 38 to limit sliding movement of the plunger Eland prevent rotational movement thereof,

The operation of the machine will now be described commencing with theparts in the posi- An unground clutch teeth 29 engage the clutch teeth28 on the ring 21. As before stated the pinion 26, spindle 24 and ring21 are continuously rotating when the machine is started and thereforerotary motion is transmitted to the clutch sleeve 30 which, through thesliding coupling transmits rotary motion to the cam sleeve 22 andin-feed cam 2|. At the commencement of this rotary motion the plunger 6|is moved against the action of its spring 62 so that the V-shaped noseB9 is disengaged from the groove 59 in the clutch sleeve and the noserides on the periphery of the sleeve. The in-feed cam 2| rotates in ananti-clockwise direction as viewed in Figure 1 so that the lever I6 ismoved about its pivot pin in a clockwise direction to transmit slidingmovement to the lead screw 1 against the action of the spring II. Thenut 6 and bracket 3 move with the lead screw and the grinding wheel isgradually fed towards the regulating wheel to remove stock camapproaches the projection 36 the clutch sleeve 30 is caused to graduallyslide along the Spindle 24 until, when the in-feed cam 2| attains theposition shown in Figure 1 the clutch teeth -29 are disengaged from theclutch teeth 23 whereby the drive to the in-feed cam is discontinued. Inthis position the highest point of the 'in-feed cam 21 is past theroller 18 which now engages the lowest point of the in-feed cam, the

drive to which is discontinued as before .described. This position ofthe in-feed cam is maintained by engagement of the V-shaped nose 60 withthe groove 59 in the clutch sleeve 39.

Immediately prior to the in-feed cam attaincommenced by the lever 49being rocked by the operator.

If it is desired that unground workpieces should be fed automatically tothe throat between the grinding and regulating wheels, instead of byhand, the lever 49 is rocked in anticlockwise direction, as Viewed inFigure 3, to

withdraw the projection 36 from the face cam 35 and the set screw 51 isadjusted to lock the abutment against the set screw 58. The cycle ofoperations is then continuous.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

l. A centreless grinding machine comprising a rotatable grinding wheel,a rotatable regulating wheel, a stationary workpiece support between thegrinding and regulating wheels, a rotary in-feed cam to control thedistance apart of the grinding wheel and regulating wheel, a clutch totransmit rotary motion to the in-feed cam, automatic means to disengagethe clutch when a workpiece has been ground, and manually operable meansto engage the clutch to enable another workpiece to be ground.

2. A centreless grinding machine comprising a rotatable grinding wheeland a cooperative regulating Wheel, said wheels having their peripheriesopposed and spaced apart and being relatively movable to vary the spacebetween them, a stationary workpiece support in the space between thewheels, means including a rotary in-feed cam for relatively moving thewheels to reduce the distance apart of their peripheries, meansincluding a clutch for transmitting rotary motion to the in-feed cam,means cooperative with'said clutch to disengage it when the distanceapart of the wheels has been reduced to a predetermined amount, andmeans operable manually and cooperative with said clutch disengagingmeans to cause engagement of the clutch for transmission of rotarymotion to the in-feed cam.

3. A centreless grinding machine comprising a rotatable grinding wheel,a rotatable regulating wheel, a stationary workpiece support between thegrinding and regulating wheels, a rotary infeed cam to control thedistance apart of the grinding wheel and regulating wheel, a clutch totransmit rotary motion to the in-feed cam, auto matic means to disengagethe clutch when a workpiece has been ground, a member adapted to berotated only when the clutch is engaged and the in-feed cam is rotated,spring-loaded retaining means so associated with said member as to holdthe in-feed cam stationary when the clutch is disengaged after aworkpiece has been ground anduntil the clutch is re-engaged, andmanually operable means to engage the clutch to enable another workpieceto be ground.

4. A centreless grinding machine comprising a rotatable grinding wheel,a rotatable regulating wheel, a stationary workpiece support between thegrinding and regulating wheels, a rotary in-feed cam to control thedistance apart of the grinding wheel and regulating wheel, a spindleadapted to be continuously driven and concentric with and rotatablerelative to the in-feed cam, a ring secured concentrically to thespindle and formed on one face with clutch teeth, a complementary clutchmember slidably mounted on the spindle, a face cam provided on theslidable clutch member, a projection which is cooperative with the facecam to cause axial displacement of the face cam and the respectiveclutch member to effect opening of the clutch and which is movable outof engagement with the face cam to allow the clutch to close andtransmit rotary motion to the in-feed cam, spring means to urge theslidable clutch member to-- wards the other clutch member, a slidingcoupling between the slidable clutch member and the in-feed cam totransmit rotary motion, and spring-loaded retaining means associatedwith a part adapted to be rotated only when the clutch members areengaged so as to hold the in-feed cam stationary after a workpiece hasbeen ground and the clutch members are disengaged and until said membersare re-engaged.

5. A centreless grinding machine comprising a rotatable grinding wheel,a rotatable regulating Wheel, a stationary workpiece support between thegrinding and regulating wheels, a rotary in-feed cam to control thedistance apart of the grinding wheel and regulating wheel, a spindleadapted to be continuously driven and concentric with and rotatablerelative to the infeed cam, a ring secured concentrically to the spindleand formed on one face with clutch teeth, a complementary clutch memberslidably mounted on the spindle, a face cam provided on the slidableclutch member, a projection which is cooperative with the face cam tocause axial displacement of the face cam and the respective clutchmember to effect opening of the clutch and which is movableout ofengagement with the face cam to allow the clutch to close and transmitrotary motion to the in-feed cam, spring means to urge the slidableclutch member towards the other clutch member, a sliding couplingbetween the slidable clutch member and the in-feed cam to transmitrotary motion, the slidable clutch member having a recess formedtherein, a plunger so arranged that it fully engages said recess whenthe clutch is open to hold the in-feed cam stationary, and spring meanstending to urge the plunger into engagement with the recess, the recessand plunger being so shaped that rotation of the slidable clutch membercauses disengagement of the plunger from the recess.

WILLIAM OGILVIE.

file of this patent:

UNITED STATES PATENTS Number Name Date 1,191,874 Day July 18, 19162,116,794 LaFleur May 10, 1938 2,295,342 Graf et a1. Sept. 8, 19422,297,045 Bergstrom Sept. 2'7, 1942 2,324,482 Carlson July 20, 1943

